March 12, 2003—In 1994, four years after the enactment of the Clean Air Act Amendments, the Environmental Protection Agency, issued its first list of allowable substitutes for CFC and HCFC refrigerants.
The EPA and its program, known as the Significant New Alternatives Policy program, or SNAP, evaluates new and existing products in eight sectors that are historically known to produce the highest volume of ozone-depleting substances. The sectors are: refrigeration and air conditioning; foam blowing; cleaning solvents; fire suppression and explosion protection; sterilants; aerosols; adhesives, coatings and inks; and tobacco expansion. A new or existing product in each of these sectors is evaluated for its effect on ozone and its potential to contribute to global warming.
This years list for the refrigeration and air conditioning sector includes six alternatives to CFCs and HCFCs for both new and retrofit equipment. A seventh, NU-22, was previously listed on the SNAP list March 2002 when it was announced that the manufacturer had reformulated the refrigerant to replace ISCEON 59, a previously accepted alternative for widely used refrigerant R-22. This year, NU-22 has been added as an accepted alternative for R-502 in industrial process refrigeration; industrial process air-conditioning; cold-storage warehouses; refrigerated transport; retail food refrigeration; commercial ice machines; water coolers and ice-skating rinks.
Of the seven refrigerants on this years list, six will not deplete ozone, however, the seventh, R-414B, will. A refrigerants ozone depleting potential (ODP) refers to the reference level of 1 assigned as an index to the baseline refrigerants CFC-11 and CFC-12. For example,
if a refrigerant has an ozone depleting potential of 0.5, a given weight of the product in the atmosphere over time would deplete half the ozone that the same weight of CFC-11 or CFC-12 would deplete.
All the refrigerant blends on this years list also have varying capacities to increase global warming; this measurement is called the refrigerants Global Warming Potential, or GWP. It is measured by comparing a given mass of chemical to the same mass of carbon dioxide over a 100-year time period. Carbon dioxides GWP is defined as 1.0. For example, a refrigerant with a GWP of 390 has nearly 400 times the ability to warm the atmosphere as the same amount of carbon dioxide. Each description of the alternatives below includes its flammability potential, its toxicity and recommended exposure data.
The EPA strongly encourages professionals to use the alternatives as recommended. Some of the new blended refrigerant alternatives may fractionate, or leak disproportionately, and need to be disposed of instead of recharged into a system. These new waste streams of useless blended refrigerants can create an extra burden when keeping records for used refrigerant disposal.
Facility managers and equipment owners may need to re-evaluate the refrigerant transition plans to incorporate the potential solutions these new refrigerants may offer.
For more on this story, including a list of the new refrigerants, contact Environmental Support Solutions.
– Robert Johnson
